The present invention relates to a digital textile printer, and more particularly a printer performing effectively not only general printing operations to a relatively thick printing material (textile fabrics or papers), such as a banner, an advertising material, or a photograph, but also textile printing operations to very thin printing material, such as textile fabrics.
Generally, in the conventional printer utilizing a technique of subtractive mixture, a digital controller sends digitalized signals to a head of the printer, so that the head may inject proper amounts of ink of three primary colors comprising magenta, yellow, and cyan, and of a black color to a printing material to produce various color tones. Therefore, the latest printer makes it possible for a user to design more easily what she/he wants.
In the technique of subtractive mixture, the head of the printer is equipped with several ink reservoirs, while each ink reservoir contains one color respectively. The head injects proper amounts of ink from each reservoir to produce a new color tone. The head is often further equipped with another ink reservoir containing special color to produce a new color tone, if necessary.
By referencing FIG. 1 and FIG. 2, the conventional digital printer will be described briefly in the following statements.
The conventional printer includes a transfer belt 5 with a rail shape on the top of a base 3, while the base 3 is supported by legs 1 contacting with the ground. The one side of a cartridge 9 is fixed with the transfer belt 5, so that a head 7 of the cartridge 9 can be moved via the transfer belt 5. In addition, a transfer axil 50 is connected with a transfer motor (not shown) within a driving panel 18 installed in the one side of the inner upper side of the base 3. Additionally, several transfer rollers 51 on the transfer axil 50 are extruded on the top of the base 3 to make a printing material 17 move to the forward direction, while a press roller 40 equipped correspondingly on the top of each transfer roller 51 presses the printing material 17 to the downward direction.
In addition, a feeding roller 11 installed in the rear side of the digital printer supplies the printing material 17 to the top of the base 3. When the cartridge 9 moves reciprocally to the left or the right direction on the top of the printing material 17, the head 7 moving in combination with the cartridge 9 injects predetermined amounts of each color from the corresponding ink reservoir to perform printing operations. As a result, the printed material is recoiled in a rewinding roller 12 located on the opposite side of the feeding roller 11.
An operation panel 16 covered by a cover 15 is equipped on the top of the base 3. Therefore, a user can input any desirable signal to be printed in the printing material 17.
In other words, as shown in FIG. 2, the printing material 17 is suspended to the feeding roller 11 in the rear of a fixing frame 10 between the legs 1, and the end of the printing material 17 passes through the top of the base 3 supported by the legs 1. In addition, the rewinding roller 12 winding the printing material 17 printed at the base 3 is in the front of the fixing frame 10.
However, the conventional printer described in the above statements has the following problems. After the printing material 17 is put between the several transfer rollers 51 and press rollers 40, the transfer roller 51 rotates to make the printing material 17 move to the front side of the base 3. When the printing material 17 is extremely thin, for example, in the case of textile printing, the speed of the printing material 17 passing through between the transfer rollers 51 and the press rollers 40 is different from that of the printing material 17 before the transfer roller 51. Therefore, a portion of the printing material 17 is often wrinkled, and the wrinkled moving printing material 17 has a tendency of inclining toward one direction only. As a result, when the printing material 17 is distorted or wrinkled, printing colors are overlapped resulting in a high fraction of defective results of the printing operations.
Additionally, the conventional digital printer does not have a feeding means drawing and rewinding the printing material 17 in constant speed to maintain the printing material 17 in a plane. Therefore, the distortion or the wrinkle of the printing material 17 is deepened more to increase the fraction of defective results of the printing operation.